Weird Looking Backwash Valve

[AJC9725]

Was helping a friend open their pool. The filter system is pretty old, and it has a backwash valve that I've never seen before. It wasn't budging when I tried to move it, so rather than break it, I figured I'd ask around to see if anyone is familiar with this black valve style and the proper way to operate it? Thanks.

 

[JamesW]

https://www.c-m-p.com/wp-content/uploads/2014/02/25831-11x-750-Pentair-Slide-Valve-Instructions.pdf

https://www.pentair.com/content/dam/extranet/product-related/product-manuals/pool-and-spa-equipment/valves/Two%20Position%20Slide%20Valves%20for%20Pool%20Filters%20Owners%20Manual%20English.pdf

Below is the procedure for backwashing a DE filter.

You have a sand filter, which is the reverse up/down for backwashing compared to DE.

 

[JamesW]

SAND FILTER OPERATION

FILTER: For normal filtering, handle should be in the UP/LOCK position.

BACKWASH: To backwash filter, turn off pump. Turn valve handle counterclockwise to OPEN position. Push handle straight DOWN as far as it will go and lock it. Restart pump. Water flow is reversed thru filter and water and dirt are directed out the valve waste line

 

[AJC9725]

Awesome. Thanks guys!

 

[JamesW]

The filter is probably over 40 years old.

The backwash valve is newer.

It should have the date on the silver label.

Also, don't lean on the filter as it will embed fiberglass into anything that makes contact with it.